December 9, 2013
How life on Earth came into existence is still one of the greatest mysteries in science but new research into the “deep biosphere” indicates that the first replicating life-forms on the planet may have originated deep underground rather than, as commonly believed, on the surface.
Scientists have now discovered microbes living and reproducing as deep as 5km (3.1 miles) below ground and studies have shown that they are likely to have survived in complete isolation from the surface biosphere for millions and perhaps even billions of years.
One of the latest studies into the deep biosphere has found that these microbes form a distinct subsurface community of genetically similar individuals despite living on opposite sides of the world. This global similarity of such an isolated life-form suggests that they may have evolved directly from a common ancestor that lived as long ago at the period when life on earth originated, some 3.5 billion years ago.